KBC: Multiple Key Generation using Key Block Chaining

Abstract

Cryptography is an important aspect of securing communications, however, the encryption scheme may be known to the attacker(s). Hence, the key can be rewarded as a crucial part of any cryptographic algorithm. With the symmetric key, researchers have developed chaining concepts where the output of one operation becomes an input to the next one. Such concept of modes of operation (Cipher Block Chaining) is integrated in this article to generate multiple key blocks. The generated keys can be provided to an individual block of plaintext for any encryption technique as per the requirements. The proposed Key Block Chaining (KBC) approach can also be referred to as a key derivation approach. The basic concepts of Advanced Encryption Standard and Message Authentication Code have also been incorporated in the proposed model to introduce randomness, and thereby, ensuring security as well as robustness. To assess the randomness of the sequence of generated keys, KBC is implemented and tested using the National Institute of Standards and Technology statistical test suite and reasonable randomness has been successfully achieved. Possible variations and key points of the proposed approach along with statistical analysis and significance of our work have been discussed.